| OCR Text |
Show 32 the series order of (H. -Cl. -OCH3• NH2) which may be considered as the increasing. perturbing powero The weaker transiion.is appar) -r ently about one-ten,h to ul tX'ayiolet a recent Whether intense as as the maih polarized absoz-pt Lon study", i a w electc dipole moment) o determine which term of Equation correct band a n of considerable +'w" w* transition (large i .f. quently it is 34 . Cotton effect arises from a component according (large magnetic moment) helps 2016 should be emphasized; conse- importa?ce to have mepns of making assignments", Tpe intensities of the B2u and Blu bands as compared to the * n ,n bands help identify them in the absorption spectra to seve provided the bands are fortitously Otherwis locatedo theFe remains the, disconcerting possibli ty of a favorable or unfavorable anisotropy factor (see band Eqation 2017)0 In other words a submege9 n *absorption miht gve rise to a large Cotton effect such that the 60-m Cotton effect characteristic of the nucleosides may be due to this transitionQ Fortunately the n w* ,nd w largely w* bands show 'I opposl te subat I'tuerrt , J • • the • pH and solvent effects as is indicative of following generl rules:33 L The, pLacemerrt of any e Lectmon ... donon (such as CIt O?H3 or 2) Qn tbe puripe or pyrimidine ring will usually red shift all 'w w* ransitions and blue-shift all n w* transitionso (One exception is the B2u band which is somewhat blue shifted by an electron-donor at C6 of the rinSQ) |
